Object based systems are generally known. Presently, the best known model for an object-based system, or architecture, is the Common Object Request Broker Architecture (CORBA), which is supported by a consortium called the Object Management Group (OMG) comprising over 700 companies. Another well known model is Microsoft's Distributed Component Object Model (DCOM), which shares many principles with CORBA. While many of the principles discussed below relate to object-based systems in general, for ease of description only, the description is directed to the specific case of CORBA. The skilled person will appreciate, however, that the principles are more widely applicable, for example to DCOM.
CORBA can be considered as a model for middleware applications, which defines how blocks of intelligence, known as objects, interact across a distributed computing and communications environment. CORBA is well documented and will not generally be considered in any depth in this description. The book “Instant CORBA” by Robert Orfali et al (published by Wiley Computer Publishing, John Wiley & Sons Inc., Copyright 10997, ISBN 0-1371-1081233-4), however, provides a comprehensive introduction into CORBA and, as such, provides background to the principles described herein.
It is usual for companies to protect their internal network, or intranet, from attacks from the public Internet by using gateways or firewalls which monitor and restrict the flow of information between the Internet and the intranet. Some companies also have a need to deploy firewalls internally to restrict and monitor the flow of information between different parts of the enterprise.
CORBA is receiving increasing attention as more and more companies adopt it as the model for the backbone for their enterprise information architectures. One of the main barriers to CORBA deployment, however, is the lack of a defined mechanism for implementing gateway or firewall technology.
Hereafter, the term ‘gateway’ will be used to describe any physical or logical system or process that can be placed between networks such as the Internet and an intranet.
It is an aim of the present invention to provide a gateway which can support CORBA and the like.